1-Adamantyltrimethylammonium hydroxide and N,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate are useful as a templating agents in the production of zeolites. A standard route to prepare ammonium salts of organic amines, such as 1-adamantyltrimethylammonium hydroxide, includes an alkylation step in which the organic amine is reacted with an alkylating agent such as dialkyl sulfates or methyl iodide. For example, U.S. Pat. No. 8,252,943 discloses a process for preparing ammonium compounds by reacting compounds containing a double-bonded nitrogen atom with a dialkyl sulfate with participation of both alkyl groups of the dialkyl sulfate and, if appropriate, subjecting the resulting ionic compound containing sulfate anions to an anion exchange. Likewise, U.S. Pat. No. 8,163,951 teaches a process for preparing quaternary ammonium compounds, which comprises reacting compounds comprising an sp3-hybridized nitrogen atom with a dialkyl sulfate or trialkyl phosphate and subjecting the resulting ammonium compound to an anion exchange. U.S. Pat. Appl. Pub. No. 2012/0010431 discloses a process for preparing 1-adamantyltrimethylammonium hydroxide that comprises reacting 1-adamantyldimethylamine with dimethyl sulfate to give 1-adamantyltrimethylammonium sulfate, which is then subjected to anion exchange with an ion exchanger loaded with OH ions. In addition, U.S. Pat. No. 4,859,442 describes at Example 1 the preparation of 1-adamantyltrimethylammonium hydroxide by alkylation of 1-adamantylamine with methyl iodide, followed by ion exchange of the iodide anions with an ion exchange resin. U.S. Pat. No. 5,645,812, likewise, teaches the preparation and use of a N,N-diethyl-3,5-dimethylpiperidinium hydroxide templating agent.
In addition, U.S. Pat. No. 6,784,307 teaches a method of preparing quaternary ammonium alkylcarbonates (such as quaternary ammonium methocarbonates), quaternary ammonium bicarbonates, and quaternary ammonium carbonates by reaction of the corresponding tertiary amines with a cyclic carbonate and methanol. Zhuoqun Zheng et al. in Adv. Synth. Catal. 2007, 349, 1095-1101 and Chinese Pat. Appl. No. CN1948268 describe a process for preparing quaternary salts from amine salts and dimethyl carbonate in the presence of ethyl methyl imidizolium salts as catalysts. The same authors describe the quaternization of amine salts without a catalyst in Chinese Pat. No. CN 101245019.
As with any chemical process, it is desirable to attain still further improvements in processes for preparing 1-adamantyltrimethyl-ammonium methylcarbonate and 1-adamantyltrimethyl-ammonium hydroxide. We have discovered a new method to produce 1-adamantyltrimethyl-ammonium methylcarbonate with a high yield.